1. Field of the Invention
This invention relates to log-splitting devices and, in particular, to self-powered log-splitting devices.
Self-powered log-splitting devices, commonly referred to as "power log splitters", typically comprise a blade or wedge that is pressed into a log or a screw that is screwed into the log. Devices that make use of a wedge and a stop member (often referred to as a "ram") can be classified by the power means used to drive the blade into the log. Thus, e.g., there are hydraulic splitters, which employ a hydraulic pump to impel a wedge into a log, and rack-and-pinion splitters in which the wedge is mounted on a rack driven by a pinion, the pinion being rotated by a motor. In an article by A. J. Hand entitled "PS Buyer's Guide to Power Log Splitters", published in Popular Science magazine, August 1979, page 101, the author states that hydraulic splitters take about 20 seconds to split logs, and that the fastest splitter known was the FXG Super Split rack-and-pinion splitter, which is said to have a cycle time of around 2 seconds. The article also acknowledges that a power log splitter may have a motor-driven worm shaft to drive the wedge into the log. In all such devices, the same power means that impels the wedge into the log also advances the wedge through the log.
2. Related Art
U.S. Pat. No. 4,176,698 to Ahlschlager et al, issued Dec. 4, 1979 and entitled "Firewood Splitting Device", discloses a log-splitting device in which a wedge is driven into a log. The wedge is connected through a transfer link or pitman 20 that is pivotably attached to the wedge at one end and at the other end to a crank fixed to a flywheel. The crank is proportioned so that the stroke is relatively long and the drive is arranged so that oscillations are fairly slow (see column 2, lines 6-11).
The prior art also discloses hand-held splitting devices that are constructed without a stop member, or ram. For example, U.S. Pat. No. 5,107,911 to Plakotaris, issued Apr. 28, 1992 and entitled "Log Splitting Device", discloses a log splitting device generally consisting of a power jack hammer equipped with a log splitting head. U.S. Pat. No. 3,371,724 to Crowell, issued Mar. 5, 1968 and entitled "Power Wedge", discloses a power wedge for splitting logs, including a drive mechanism for the wedge that comprises a rotating cam against which a drive rod for the wedge is disposed.